1. Field of the Invention
This invention relates to concentrate compositions suitable for dilution with water to produce aqueous based compositions that are useful for lubricating the surfaces of metals, especially steel, before and during cold forming operations, particularly cold drawing operations. The metal surfaces may or may not have other surface layers such as phosphate conversion coatings, anodized coatings, or the like underlying the lubricant coating produced on the surface by using this invention. The invention also relates to the lubricating compositions ready for immediate use and to cold working processes utilizing such compositions.
2. Statement of Related Art
A very wide variety of materials have been taught in the art for lubricating metals before cold working. The composition believed to be most commonly used now commercially combines alkali metal and alkaline earth metal soaps, particularly stearates including zinc stearate. These soap containing compositions of the prior art give excellent lubricating performance, but generate dusts which can annoying to users with less than optimal ventilation systems. There has consequently been an incentive to find other lubricating compositions that will give lubricating performance at least as good as that of the prior art soap based compositions and generate less dust during use. Some teachings along this line believed to be those most nearly pertinent to the present invention are reviewed below.
Published Japanese Application No. 63-301297 according to an abstract thereof teaches an emulsion type metal rolling oil composition containing a lubricating oil component selected from animal and vegetable oils and fats, mineral oils, and fatty acid esters along with another component which may be a copolymer of styrene and maleic acid.
Published Japanese Application No. 63-008489 according to an abstract thereof teaches an aqueous lubricant for the cold forming of metal. The lubricant contains an acrylate based heat curing resin, wax, and surfactant. The resin is a polymer of at least four monomers, of which two may be styrene and maleic acid or its salts, the others being acrylates.
Published Japanese Application No. 60-099200 according to an abstract thereof teaches a two step process for preparing metals for cold forming. In the first step a mixture of water soluble thermoplastic resin and a melamine adduct of cyanuric or isocyanuric acid is applied to the metal surface and dried. The thermoplastic resin may be a copolymer of maleic acid and styrene. In a second step a conventional lubricating soap, oil, or solid lubricant is applied.
Published Japanese Application No. 59-149995 according to an abstract thereof teaches a lubricating composition for metal working comprising wax, fatty acid, amine or amine derivatives, an alkali soluble resin, and an extreme pressure additive. The wax may be a paraffin or polyolefin wax and the alkali soluble resin may be a styrene-maleic acid resin.
U.S. Pat. Nos. 4,403,490 and 4,416,132 according to abstracts thereof teach lubricant compositions for forming cans from untinned steel. One such composition comprises terpene-phenol resin, esterified styrene-maleic anhydride, synthetic polymethylene wax, unsaturated fatty acid, amines, potassium hydroxide, and solid lubricants.
Published Japanese Application No. 52-065748 according to an abstract thereof teaches metal lubricating oils made by adding a styrene copolymer, which may be a polymer with maleic anhydride acid or ester, to a conventional composition such as mineral oil or fat.
Published Soviet Patent application No. 433,201 according to an abstract thereof teaches a lubricant composition for cold working metals that comprises sodium soap, styrene-maleic anhydride copolymer, free fatty acid, water, and mineral oil.
U.S. Pat. Nos. 3,657,123, 3,645,897, 3,629,112, and 3,527,726 according to abstracts thereof all teach lubricating compositions containing amine salts of partial esters of styrene-maleic anhydride copolymers with alcohols, which may be alkoxylated alcohols.
Published European Patent Application No. 267,558 teaches metalworking lubricants containing a water soluble thermoplastic polymer, the polymer containing some hydrophobic groups, combined with an ethoxylated alcohol. Although the broadest teachings of this reference are to any water soluble polymer containing hydrophobic groups in which at least some of the segments include at least two hydrophobic groups, the only examples of the polymers taught are polyurethanes.
U.S. Pat. Nos. 4,731,190, 4,654,155, and 4,636,321 all teach various metal working lubricant compositions including alkoxylated alcohols.
U.S. Pat. No. 4,931,197 teaches as metal working lubricants aqueous emulsions of copolymers of (i) alpha-olefins and (ii) esters of unsaturated carboxylic acids with ethoxylated alcohols.
U.S. Pat. No. 3,568,486 of Mar. 9, 1971 to Rosenberg et al. teaches a general scheme of lubricating metal for cold working involving a "permanent" coating of a resinous lubricant which is temporarily softened by an overlay coating of liquid containing a plasticizer for resinous coating when greater lubricity is needed. The preferred resinous composition is alkali soluble acrylic and/or methacrylic acid polymer, mixed with a relatively minor amount of styrene-maleic acid copolymer. This may be softened when desired with mineral oil, lard, ethylene glycol, or the like.